Seismic risk analysis of concrete moment-resisting frames against near-fault earthquakes

2020 ◽  
pp. 1748006X2094047
Author(s):  
Ehsan Khojastehfar ◽  
Farzad Mirzaei Aminian ◽  
Hamid Ghanbari
Keyword(s):  
Risk Analysis ◽  
Seismic Risk ◽  
Ground Motions ◽  
Seismic Risk Analysis ◽  
Strong Ground Motions ◽  
Near Fault ◽  
Moment Resisting Frames ◽  
Short Period ◽  
Moment Resisting ◽  
Strong Ground

Characteristics of earthquake strong ground motions play an important role in the calculation of seismic-induced risk imposed on the structures. Distinguished features exist in movements recorded near seismic sources, as a result of a substantial amount of energy in a short period of record arrival time. In this article, seismic risk analysis of concrete moment-resisting frames due to near-fault strong ground motion is calculated and compared with that of caused by far-field strong ground motions. To achieve this goal, three moment-resisting frames with 4, 6, and 10 stories were designed based on international seismic design code. These frames are modeled applying modified Ibarra–Krawinkler moment–rotation nonlinear model in which strength and stiffness deterioration are involved. Seismic risk analysis of the frames is implemented using the Pacific Earthquake Engineering Research Center approach. Through this approach, probabilistic seismic hazard, probabilistic structural demand, probabilistic structural damage, and probabilistic loss curves are combined. Mean annual frequency of exceedance of seismic-induced losses presents probabilistic seismic risk of the sampled frames. According to the achieved results, the four-story frame (representative of low-rise frames) is more prone to be affected by near-fault strong ground motions in view of calculated seismic-induced risks.

Factors Influencing Maximum and Residual Deformations of SDOF Systems Subjected to Large Ground Motions

2011 ◽  
Vol 243-249 ◽  
pp. 170-177
Author(s):  
Peng Pan ◽  
Yu Zhang ◽  
Shi Yan Song ◽  
Lie Ping Ye
Keyword(s):  
Structural Parameters ◽  
Ground Motions ◽  
Stiffness Degradation ◽  
Maximum Deformation ◽  
Strong Ground Motions ◽  
Long Period ◽  
Short Period ◽  
Residual Deformations ◽  
Yield Force ◽  
Strong Ground

The maximum and residual deformations of structures subjected to strong ground motions are the most importance indexes, particularly under the performance-based design framework, thus understanding the influencing factors is of great importance to seismic design. In this study, single degree of freedom (SDOF) systems with varying structural properties are analyzed using a series of strong ground motions from FEM/SAC project. The influences of three structural parameters, i.e., yield force, second stiffness after yielding, and stiffness degradation, on the maximum and residual deformations are investigated based on the statistics of the analysis results. The analysis results suggest the follows: (1) larger yield forces lead to smaller residual and maximum deformations for short period structures, and they lead to smaller residual deformations but no necessarily smaller maximum deformation for intermediate and long period structures; (2) larger second stiffness lead to smaller residual and maximum deformations for short period structures, and they lead to smaller residual deformations but no necessarily smaller maximum deformation for intermediate and long period structures; (3) smaller stiffness degradation index leads to smaller maximum deformations but larger residual deformations.

Seismic Behavior of MFPS Isolated Structure Under Near-Fault Sources and Strong Ground Motions With Long Predominant Periods

2003 ◽  
Author(s):  
C. S. Tsai ◽  
Tsu-Cheng Chiang ◽  
Bo-Jen Chen
Keyword(s):  
Ground Motions ◽  
Experimental Studies ◽  
Shaking Table ◽  
Well Performance ◽  
Pendulum System ◽  
Strong Ground Motions ◽  
Near Fault ◽  
Base Isolator ◽  
Isolated Structures ◽  
Strong Ground

Base isolation, which has been recognized as a very promising way for upgrading the earthquake-proof capability of existing structures both from theoretical and experimental studies. However, some researchers suspect the efficiency of base isolator under near-fault earthquakes and strong ground motions with long predominant periods. It is suggested from previous studies that earthquakes with long predominant periods always cause severe responses of base-isolated structures. In view of this, a new base isolator called as Multiple-Friction Pendulum System (MFPS) has been proposed in this study to improve the shortcoming of those undesirable phenomenon of base-isolated structures. In order to evaluate the efficiency of MFPS isolators, the shaking table tests of a 3-story steel structure have been performed at NCREE in Taiwan. Experimental results show that the proposed isolator still posses well performance under near source excitations and strong ground motions with long period predominant periods. Therefore, the proposed base isolator can be recognized as a very promising tool for enhancing the seismic-resistance of a structure near seismic faults or on a soft deposit soil.

Sign in / Sign up

Export Citation Format

Share Document